Can You Freeze Yogurt Starter? Everything You Should Know

Yogurt starter is essential to making homemade yogurt. If you’re a bit of a yogurt fanatic, you can keep your starter cultures ‘fed’ by making new batches of yogurt every few days.

But what do you do if you can’t do that? Perhaps you’re going away on vacation for a few days and know you won’t be able to keep your starter culture going. Is your culture doomed to ‘die’? Are your chances of developing an heirloom yogurt culture to pass down the generations a distant dream?

Well, don’t despair. The good news is that yes, you can freeze yogurt starter! You can keep an active yogurt starter in the freezer for up to 4 weeks. Freeze-dried yogurt started can be stored even longer, lasting up to 3 months in the freezer.

Read on to learn everything you need to know about freezing yogurt starter.

The Quick Answer – Can Yogurt Starter Be Frozen?

Yup, you can certainly freeze yogurt starter. However, the method you use will depend on if the yogurt starter is freeze-dried, activated, or dehydrated.

If the yogurt starter is freeze-dried or dehydrated, it’s going to be more shelf-stable. This means that it’s easier to freeze and store.

If you’re dealing with a yogurt starter culture that’s already activated, then it’s not quite as simple. When you freeze a live yogurt starter culture, you can expect some of the bacteria to die in the process. However, it’s only some and it will still be fine to use later on as long as you freeze it the proper way. 

How Long Can You Freeze Yogurt Starter For?

Again, how long you can freeze a yogurt starter depends on if it’s freeze-dried, dehydrated, or activated.

If it’s either freeze-dried or dehydrated it will last much longer. You can safely keep these types of yogurt starters in the freezer for up to three months safely.

On the other hand, if it’s been activated then it won’t last nearly as long. Active yogurt starter should only be kept in the freezer for up to one month. 

How to Freeze Dry Yogurt Starter

If your yogurt culture is dehydrated or freeze-dried, you can significantly extend its life by freezing it.

Your bag or box should include a “best before date” that you should always adhere to. When frozen, you may keep your cultures fresh for up to three months.

Ideally, you should freeze your yogurt beginning in its original container. If you’ve opened it to use a portion of it, make sure it has an airtight seal or move the contents to a freezer-safe glass airtight container. A silicone freezer bag is another option.

Because yogurt contains probiotics, you want to preserve the bacteria’s health as well as possible, therefore avoid storing it in plastic if possible. 

How to Freeze Active Yogurt Starter

Freezing active yogurt start is a bit more complex as you have to deal with live bacteria, not bacteria that is inactive. But, if you’ve already made yogurt and want to keep some for future use, then you can still store it in the freezer without a problem. 

Freezing a yogurt starter is a convenient method to take a break from yogurt making without jeopardizing the viability of your culture.

Freeze your yogurt in proper serving sizes that will culture a serving of milk for the best results. If you wish to culture 1 cup of milk, for example, freeze your yogurt in 1 tablespoon portions. In this way, ice cube trays can be particularly helpful for freezing yogurt because they precisely fit 1-2 teaspoons.

When your yogurt is completely frozen, transfer the cubes to a freezer-safe, airtight container. Instead of plastic, try using freezer-safe glass storage containers or reusable silicone bags.

The longer it’s stored in the freezer, the more bacteria will die, meaning that it’s a less viable yogurt starter. You should aim to store the active yogurt starter for no more than one month. 

How to Thaw Yogurt Starter

There is really only one way to thaw frozen starter, and that’s in the fridge.

I usually let it defrost in the fridge overnight if I remember. You don’t need all night though. If I’m short on time, I take a container from the freezer in the morning and leave it on the counter for a few hours. It’s completely thawed by the time I need it. Just be sure not to leave it on the counter for too long as you run the risk of it spoiling.

Simply do not use heat to defrost the beginning (microwave or stove). Heat will destroy your active cultures and render your starter ineffective.

What’s The Best Way to Store Yogurt Cultures?

Unless otherwise indicated, unopened packets of freeze-dried or dehydrated yogurt starter are considered shelf-stable and can be stored in any cold, dry place that does not receive direct exposure to heat or light. This means that even in your pantry you can store a dehydrated or freeze-dried yogurt starter. 

But, if you aren’t going to use it for a few months, the best approach is to keep it airtight and refrigerated. If you have any doubts about when you’ll use it, it’s best to be safe and keep the package in the fridge or in the freezer until you plan on using it. 

How to Tell if Homemade Yogurt Has Gone Bad

While the time it takes for yogurt to go bad varies depending on whether it’s Greek, frozen, or drinkable yogurt. However, there are a few basic techniques to determine if the yogurt has gone sour. If only one of these criteria is present, the yogurt may still be salvageable if consumed immediately. However, if more than one, or worse, all of the criteria are present, you should unquestionably discard the yogurt. Here are some things to look out for.


First, check the color. If any discoloration in the yogurt is visible it should be thrown out. A cloudy brown or yellow liquid on the surface is a warning sign. Mold, whether white or black, may also emerge. Don’t believe that you can just eliminate the undesirable bits and consume the rest. There may be areas that have deteriorated to the point that you cannot see them with the naked eye. The first indication of discoloration indicates that the yogurt should be discarded.


Next, give it a smell. The scent of the yogurt will tell you whether it has gone sour.

Spoiled yogurt often has a rotten odor that is extremely unpleasant. It will have a terrible odor, similar to rotten milk. If the yogurt is just starting to go bad but is still edible, the stench will be milder. It might be difficult to decide whether or not to consume it at that time. The stench, however, will not mislead you when the yogurt has become entirely inedible.


Lastly, check the texture. The consistency of the yogurt will likely tell you if it has gone sour or not. If the texture has turned lumpy, similar to cottage cheese, it’s best to simply discard it. A watery liquid will also ooze to the surface of bad yogurt. If it lacks the creamy, smooth smoothness that well-set yogurt should have, it’s likely that the yogurt has gone bad.